package com.example.lotterysystem.service.impl;

import com.example.lotterysystem.common.errorcode.ServiceErrorCodeConstants;
import com.example.lotterysystem.common.exception.ServiceException;
import com.example.lotterysystem.common.utils.JacksonUtil;
import com.example.lotterysystem.common.utils.RedisUtil;
import com.example.lotterysystem.controller.param.CreateActivityParam;
import com.example.lotterysystem.controller.param.CreatePrizeByActivityParam;
import com.example.lotterysystem.controller.param.CreateUserByActivityParam;
import com.example.lotterysystem.controller.param.PageParam;
import com.example.lotterysystem.dao.dataobject.ActivityDO;
import com.example.lotterysystem.dao.dataobject.ActivityPrizeDO;
import com.example.lotterysystem.dao.dataobject.ActivityUserDO;
import com.example.lotterysystem.dao.dataobject.PrizeDO;
import com.example.lotterysystem.dao.mapper.*;
import com.example.lotterysystem.service.ActivityService;
import com.example.lotterysystem.service.dto.ActivityDTO;
import com.example.lotterysystem.service.dto.ActivityDetailDTO;
import com.example.lotterysystem.service.dto.CreateActivityDTO;
import com.example.lotterysystem.service.dto.PageListDTO;
import com.example.lotterysystem.service.enums.ActivityPrizeStatusEnum;
import com.example.lotterysystem.service.enums.ActivityPrizeTiersEnum;
import com.example.lotterysystem.service.enums.ActivityStatusEnum;
import com.example.lotterysystem.service.enums.ActivityUserStatusEnum;
import lombok.extern.java.Log;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import org.springframework.util.CollectionUtils;
import org.springframework.util.StringUtils;

import java.util.Collections;
import java.util.List;
import java.util.Optional;
import java.util.stream.Collectors;

@Service
public class ActivityServiceImpl implements ActivityService {

    private static final Logger logger = LoggerFactory.getLogger(ActivityServiceImpl.class);

    /**
     * 活动缓存前缀, 为了区分业务
     */
    private final String ACTIVITY_PREFIX = "ACTIVITY_";
    /**
     * 活动缓存过期时间
     */
    private final Long ACTIVITY_TIMEOUT = 60 * 60 * 24 * 3l;

    @Autowired
    private UserMapper userMapper;

    @Autowired
    private PrizeMapper prizeMapper;

    @Autowired
    private ActivityMapper activityMapper;

    @Autowired
    private ActivityUserMapper activityUserMapper;

    @Autowired
    private ActivityPrizeMapper activityPrizeMapper;

    @Autowired
    private RedisUtil redisUtil;

    @Override
    @Transactional(rollbackFor = Exception.class)
    public CreateActivityDTO createActivity(CreateActivityParam param) {
        // 校验活动信息是否正确
        checkActivityInfo(param);

        // 保存活动信息
        ActivityDO activityDO = new ActivityDO();
        activityDO.setActivityName(param.getActivityName());
        activityDO.setDescription(param.getDescription());
        activityDO.setStatus(ActivityStatusEnum.RUNNING.name());
        activityMapper.insert(activityDO);

        // 保存活动关联的奖品信息
        List<CreatePrizeByActivityParam> prizeParams = param.getActivityPrizeList();
        List<ActivityPrizeDO> activityPrizeDOList = prizeParams.stream()
                .map(prizeParam->{
                    ActivityPrizeDO activityPrizeDO = new ActivityPrizeDO();
                    activityPrizeDO.setActivityId(activityDO.getId());
                    activityPrizeDO.setPrizeId(prizeParam.getPrizeId());
                    activityPrizeDO.setPrizeAmount(prizeParam.getPrizeAmount());
                    activityPrizeDO.setPrizeTiers(prizeParam.getPrizeTiers());
                    activityPrizeDO.setStatus(ActivityPrizeStatusEnum.INIT.name());
                    return activityPrizeDO;
                }).collect(Collectors.toList());
        activityPrizeMapper.batchInsert(activityPrizeDOList);

        // 保存活动关联的人员信息
        List<CreateUserByActivityParam> userParams = param.getActivityUserList();
        List<ActivityUserDO> activityUserDOList = userParams.stream()
                .map(userParam->{
                    ActivityUserDO activityUserDO = new ActivityUserDO();
                    activityUserDO.setActivityId(activityDO.getId());
                    activityUserDO.setUserId(userParam.getUserId());
                    activityUserDO.setUserName(userParam.getUserName());
                    activityUserDO.setStatus(ActivityUserStatusEnum.INIT.name());
                    return activityUserDO;
                }).collect(Collectors.toList());
        activityUserMapper.batchInsert(activityUserDOList);

        //整合完整的活动信息, 存放redis
        //activityId: ActivityDetailDTO:活动信息+奖品信息+人员信息

        //需要先获取奖品基本属性列表
        //获取需要查询的奖品id
        List<Long> prizeIds = param.getActivityPrizeList().stream()
                .map(CreatePrizeByActivityParam::getPrizeId)
                .distinct()
                .collect(Collectors.toList());
        List<PrizeDO> prizeDOList = prizeMapper.batchSelectByIds(prizeIds);

        ActivityDetailDTO detailDTO = convertToActivityDetailDTO(activityDO, activityUserDOList, prizeDOList, activityPrizeDOList);

        //存入缓存
        cacheActivity(detailDTO);

        // 构造返回
        CreateActivityDTO createActivityDTO = new CreateActivityDTO();
        createActivityDTO.setActivityId(activityDO.getId());

        return createActivityDTO;
    }

    /**
     * 翻页查询活动摘要列表
     * @param param
     * @return
     */
    @Override
    public PageListDTO<ActivityDTO> findActivityList(PageParam param) {
        // 获取活动总量
        int total = activityMapper.count();

        // 获取当前页列表
        List<ActivityDO> activityDOList = activityMapper.selectActivityList(param.offset(), param.getPageSize());

        List<ActivityDTO> activityDTOList = activityDOList.stream()
                .map(activityDO -> {
                    ActivityDTO activityDTO = new ActivityDTO();
                    activityDTO.setActivityId(activityDO.getId());
                    activityDTO.setActivityName(activityDO.getActivityName());
                    activityDTO.setDescription(activityDO.getDescription());
                    activityDTO.setStatus(ActivityStatusEnum.forName(activityDO.getStatus()));
                    return activityDTO;
                }).collect(Collectors.toList());

        return new PageListDTO<>(total, activityDTOList);
    }

    /**
     * 获取活动详情
     * @param activityId
     * @return
     */
    @Override
    public ActivityDetailDTO getActivityDetail(Long activityId) {
        if(null == activityId) {
            logger.warn("查询活动详细信息失败, activityId 为空!");
        }
        //查询 redis
        ActivityDetailDTO detailDTO = getActivityFromCache(activityId);
        if(null != detailDTO) {
            logger.info("查询活动详细信息成功, detailDTO{}", JacksonUtil.writeValueAsString(detailDTO));
            return detailDTO;
        }

        //如果redis不存在, 查表

        //活动表
        ActivityDO activityDO = activityMapper.selectById(activityId);

        //活动奖品表
        List<ActivityPrizeDO> activityPrizeDOList = activityPrizeMapper.selectByActivityId(activityId);

        //活动人员表
        List<ActivityUserDO> activityUserDOList = activityUserMapper.selectByActivityId(activityId);

        //奖品表:先获取要查询的奖品id
        List<Long> prizeIds = activityPrizeDOList
                .stream()
                .map(ActivityPrizeDO::getPrizeId).collect(Collectors.toList());
        List<PrizeDO> prizeDOList = prizeMapper.batchSelectByIds(prizeIds);

        //整合活动详情信息, 存放redis
        detailDTO = convertToActivityDetailDTO(activityDO, activityUserDOList, prizeDOList, activityPrizeDOList);
        cacheActivity(detailDTO);

        //返回
        return detailDTO;
    }

    /**
     * 缓存获得信息
     * @param activityId
     */
    @Override
    public void cacheActivity(Long activityId) {

        if(null == activityId) {
            logger.warn("要缓存的活动 activityId 为空!");
            throw new ServiceException(ServiceErrorCodeConstants.CACHE_ACTIVITY_ID_IS_EMPTY);
        }

        // 查询表数据: 活动表, 关联奖品, 关联人员, 奖品信息表
        //活动表
        ActivityDO activityDO = activityMapper.selectById(activityId);
        if(null == activityDO) {
            logger.error("要缓存的活动id有误!");
            throw new ServiceException(ServiceErrorCodeConstants.VERIFICATION_CODE_ERROR);
        }

        //活动奖品表
        List<ActivityPrizeDO> activityPrizeDOList = activityPrizeMapper.selectByActivityId(activityId);

        //活动人员表
        List<ActivityUserDO> activityUserDOList = activityUserMapper.selectByActivityId(activityId);

        //奖品表:先获取要查询的奖品id
        List<Long> prizeIds = activityPrizeDOList
                .stream()
                .map(ActivityPrizeDO::getPrizeId).collect(Collectors.toList());
        List<PrizeDO> prizeDOList = prizeMapper.batchSelectByIds(prizeIds);

        //整合活动详情信息, 存放redis
        ActivityDetailDTO detailDTO = convertToActivityDetailDTO(activityDO, activityUserDOList,
                                                                prizeDOList, activityPrizeDOList);
        // 整个完整的活动信息并缓存
        cacheActivity(detailDTO);
    }

    /**
     * 缓存完整的活动信息
     * @param detailDTO
     */
    private void cacheActivity(ActivityDetailDTO detailDTO) {
        // key: ACTIVITY_activityId: ACTIVITY_12
        // value: activityDetailDTO(json)
        if(null == detailDTO || null == detailDTO.getActivityId()) {
            logger.warn("cacheActivity 要缓存的活动信息不存在!");
            return;
        }

        try {
            redisUtil.set(ACTIVITY_PREFIX+detailDTO.getActivityId(),
                    JacksonUtil.writeValueAsString(detailDTO),
                    ACTIVITY_TIMEOUT);
        }catch (Exception e) {
            logger.error("缓存活动异常,ActivityDetailDTO={} ", detailDTO, e);
        }
    }

    /**
     * 根据活动id从缓存中获取活动详情信息
     * @param activityId
     * @return
     */
    private ActivityDetailDTO getActivityFromCache(Long activityId) {
        if(null == activityId) {
            logger.warn("获取缓存活动数据的 activityId 为空");
            return null;
        }
        try {
            String str = redisUtil.get(ACTIVITY_PREFIX + activityId);
            if(!StringUtils.hasText(str)) {
                logger.info("获取缓存活动数据为空, key={}", ACTIVITY_PREFIX + activityId);
                return null;
            }
            ActivityDetailDTO detailDTO = JacksonUtil.readValue(str, ActivityDetailDTO.class);
            return detailDTO;
        }catch (Exception e) {
            logger.error("从缓存中获取活动信息异常, key={}", ACTIVITY_PREFIX + activityId, e);
            return null;
        }
    }

    /**
     * 整合活动信息
     * @param activityDO
     * @param activityUserDOList
     * @param prizeDOList
     * @param activityPrizeDOList
     * @return
     */
    private ActivityDetailDTO convertToActivityDetailDTO(ActivityDO activityDO,
                                            List<ActivityUserDO> activityUserDOList,
                                            List<PrizeDO> prizeDOList,
                                            List<ActivityPrizeDO> activityPrizeDOList) {
        ActivityDetailDTO detailDTO = new ActivityDetailDTO();
        detailDTO.setActivityId(activityDO.getId());
        detailDTO.setActivityName(activityDO.getActivityName());
        detailDTO.setDesc(activityDO.getDescription());
        detailDTO.setStatus(ActivityStatusEnum.forName(activityDO.getStatus()));
        //apDO: {prizeId, amount, status}, {prizeId, amount, status},...
        //PDO: {prizeId, name, ...}, {prizeId, name, ...}, {prizeId, name, ...},..,.
        List<ActivityDetailDTO.PrizeDTO> prizeDTOList = activityPrizeDOList.stream()
                .map(apDO -> { // apDo -> activityPrizeDO
                    ActivityDetailDTO.PrizeDTO prizeDTO = new ActivityDetailDTO.PrizeDTO();
                    prizeDTO.setPrizeId(apDO.getPrizeId());
                    Optional<PrizeDO> optionalPrizeDO = prizeDOList.stream()
                            .filter(
                                prizeDO -> prizeDO.getId().equals(apDO.getPrizeId()))
                            .findFirst();

                    //如果PrizeDO为空, 不执行当前方法, 不为空才执行
                    optionalPrizeDO.ifPresent(prizeDO -> {
                        prizeDTO.setName(prizeDO.getName());
                        prizeDTO.setImageUrl(prizeDO.getImageUrl());
                        prizeDTO.setPrice(prizeDO.getPrice());
                        prizeDTO.setDescription(prizeDO.getDescription());
                    });

                    prizeDTO.setTiers(ActivityPrizeTiersEnum.forName(apDO.getPrizeTiers()));
                    prizeDTO.setPrizeAmount(apDO.getPrizeAmount());
                    prizeDTO.setStatus(ActivityPrizeStatusEnum.forName(apDO.getStatus()));
                    return prizeDTO;
                }).collect(Collectors.toList());
        detailDTO.setPrizeDTOList(prizeDTOList);

        List<ActivityDetailDTO.UserDTO> userDTOList = activityUserDOList.stream()
                .map(auDO -> { //auDO->activityUserDO
                    ActivityDetailDTO.UserDTO userDTO = new ActivityDetailDTO.UserDTO();
                    userDTO.setUserId(auDO.getUserId());
                    userDTO.setUserName(auDO.getUserName());
                    userDTO.setStatus(ActivityUserStatusEnum.forName(auDO.getStatus()));
                    return userDTO;
                }).collect(Collectors.toList());
        detailDTO.setUserDTOList(userDTOList);

        return detailDTO;
    }

    /**
     * 校验活动有效性
     * @param param
     */
    private void checkActivityInfo(CreateActivityParam param) {
        if(null == param) {
            throw new ServiceException(ServiceErrorCodeConstants.CREATE_ACTIVITY_INTO_IS_EMPTY);
        }
        // 人员 id 在人员表中是否存在
        List<Long> userIds = param.getActivityUserList()
                .stream()
                .map(CreateUserByActivityParam::getUserId)
                .distinct()//去重
                .collect(Collectors.toList());
        List<Long> existUserIds = userMapper.selectExistByIds(userIds);

        if(CollectionUtils.isEmpty(existUserIds)) {
            throw new ServiceException(ServiceErrorCodeConstants.ACTIVITY_USER_ERROR);
        }

        userIds.forEach(id->{
            if(!existUserIds.contains(id)) {
                throw new ServiceException(ServiceErrorCodeConstants.ACTIVITY_USER_ERROR);
            }
        });

        // 奖品id在奖品表中是否存在
        List<Long> prizeIds = param.getActivityPrizeList()
                .stream()
                .map(CreatePrizeByActivityParam::getPrizeId)
                .distinct()
                .collect(Collectors.toList());
        List<Long> existsPrizeIds = prizeMapper.selectExistsByIds(prizeIds);

        if(CollectionUtils.isEmpty(existsPrizeIds)) {
            throw new ServiceException(ServiceErrorCodeConstants.ACTIVITY_PRIZE_ERROR);
        }

        prizeIds.forEach(id->{
            if(!existsPrizeIds.contains(id)) {
                throw new ServiceException(ServiceErrorCodeConstants.ACTIVITY_PRIZE_ERROR);
            }
        });

        // 人员数量大于等于奖品数量
        int userAmount = param.getActivityUserList().size();
        long prizeAmount = param.getActivityPrizeList()
                .stream()
                .mapToLong(CreatePrizeByActivityParam::getPrizeAmount)
                .sum();
        if(userAmount < prizeAmount) {
            throw new ServiceException(ServiceErrorCodeConstants.USER_PRIZE_AMOUNT_ERROR);
        }

        //校验活动奖品等级有效性
        param.getActivityPrizeList().forEach(prize -> {
            if(null == ActivityPrizeTiersEnum.forName(prize.getPrizeTiers())) {
                throw new ServiceException(ServiceErrorCodeConstants.ACTIVITY_PRIZE_TIERS_ERROR);
            }
        });
    }
}
